The overall objective is elucidation of the function and structure of the ionic channels in excitable membranes. Experiments are performed usually on squid giant axons that are internally perfused and subjected to voltage clamp. Specific projects include 1) attempting to understand the relaton between opening of the sodium channels and the non-linear component of capacitive current that is called gating current. This is being studied by kinetic analysis, and by the use of substances that interfere with the opening and closing of the channels. 2) Measurement of current fluctuations, and, hopefully, single channel currents. 3) Study of the influence of various species of inorganic cations on the gating properties of channels.